1000 Examples Programming In Python

First steps....58

What is Python?....58

What is needed to write a program?....58

The source (code) of Python....59

Python 2 vs. Python 3....59

Installation....59

Installation on Linux....60

Installation on Apple Mac OSX....60

Installation on MS Windows....60

Editors, IDEs....60

Documentation....62

Program types....62

Python on the command line....63

First script - hello world....63

Examples....63

Comments....64

Variables....64

Exercise: Hello world....64

What is programming?....64

What are the programming languages....65

A written human language....65

A programming language....65

Words and punctuation matter!....65

Literals, Value Types in Python....66

Floating point limitation....66

Value Types in Numpy....66

Rectangular (numerical operations)....67

Multiply string....67

Add numbers....67

Add strings....67

Exercise: Calculations....67

Solution: Calculations....68

Second steps....69

Modules....69

A main function....69

The main function - called....69

Indentation....70

Conditional main....70

Input - Output I/O....70

print in Python 2....71

print in Python 3....71

print in Python 2 as if it was Python 3....72

Exception: SyntaxError: Missing parentheses in call....72

Prompting for user input in Python 2....72

Prompting for user input in Python 3....73

Python2 input or raw_input?....74

Prompting both Python 2 and Python 3....74

Add numbers entered by the user (oups)....74

Add numbers entered by the user (fixed)....75

How can I check if a string can be converted to a number?....75

Converting string to int....76

Converting float to int....76

Conditionals: if....77

Conditionals: if - else....77

Conditionals: if - else (other example)....77

Conditionals: else if....77

Conditionals: elif....78

Ternary operator....78

Case or Switch in Python....79

Exercise: Rectangular....79

Exercise: Calculator....79

Exercise: Standard Input....79

Solution: Area of rectangular....79

Solution: Calculator....80

Command line arguments....81

Command line arguments - len....82

Command line arguments - exit....82

Exercise: Rectangular (argv)....82

Exercise: Calculator (argv)....82

Solution: Area of rectangular (argv)....82

Solution: Calculator eval....83

Solution: Calculator (argv)....83

Compilation vs. Interpretation....84

Is Python compiled or interpreted?....85

Flake8 checking....85

Numbers....86

Numbers....86

Operators for Numbers....86

Integer division and the future....87

Pseudo Random Number....88

Fixed random numbers....88

Rolling dice - randrange....88

Random choice....89

built-in method....89

Exception: TypeError: ‘module’ object is not callable....89

Fixing the previous code....90

Exception: AttributeError: module ‘random’ has no attribute....90

Exercise: Number guessing game - level 0....91

Exercise: Fruit salad....91

Solution: Number guessing game - level 0....91

Solution: Fruit salad....92

Boolean....93

if statement again....93

True and False....93

Boolean....94

True and False values in Python....94

Comparision operators....95

Do NOT Compare different types....95

Boolean operators....96

Boolean truth tables....97

Short circuit....97

Short circuit fixed....98

Incorrect use of conditions....98

Exercise: compare numbers....99

Exercise: compare strings....99

Solution: compare numbers....100

Solution: compare strings....100

Strings....102

Single quoted and double quoted strings....102

Long lines....102

Triple quoted strings (multiline)....103

String length (len)....104

String repetition and concatenation....104

A character in a string....105

String slice (instead of substr)....105

Change a string....105

How to change a string....106

String copy....106

String functions and methods (len, upper, lower)....107

index in string....107

index in string with range....107

rindex in string with range....108

find in string....108

Find all in the string....109

in string....109

index if in string....109

Encodings: ASCII, Windows-1255, Unicode....110

raw strings....110

ord....110

ord in a file....111

chr - number to character....111

Exercise: one string in another string....113

Exercise: to ASCII CLI....113

Exercise: from ASCII CLI....113

Solution: one string in another string....114

Solution: compare strings....114

Solution: to ASCII CLI....114

Solution: from ASCII CLI....115

Loops....116

Loops: for-in and while....116

for-in loop on strings....116

for-in loop on list....116

for-in loop on range....117

Iterable, iterator....117

for in loop with early end using break....117

for in loop skipping parts using continue....117

for in loop with break and continue....118

while loop....118

Infinite while loop....119

While with complex expression....119

While with break....119

While True....120

Duplicate input call....120

Eliminate duplicate input call....120

do while loop....120

while with many continue calls....121

Break out from multi-level loops....121

Exit vs return vs break and continue....121

Exercise: Print all the locations in a string....121

Exercise: Number guessing game....122

Exercise: MasterMind....123

Exercise: Count unique characters....123

Solution: Print all the locations in a string....123

Solution 1 for Number Guessing....124

Solution for Number Guessing (debug)....124

Solution for Number Guessing (move)....125

Solution for Number Guessing (multi-game)....126

Solution: MasterMind....127

Solution: Count unique characters....127

MasterMind to debug....128

PyCharm....130

PyCharm Intro....130

PyCharm Project....130

PyCharm Files....130

PyCharm - run code....130

PyCharm Python console at the bottom left....131

Refactoring example (with and without pycharm)....131

Formatted printing....132

format - sprintf....132

Examples using format - indexing....132

Examples using format with names....133

Format columns....133

Examples using format - alignment....133

Format - string....134

Format characters and types....134

Format floating point number....134

f-strings (formatted string literals)....135

printf using old %-syntax....135

Format braces, bracket, and parentheses....135

Examples using format with attributes of objects....136

raw f-strings....136

Lists....137

Anything can be a lists....137

Any layout....137

Lists....138

List slice with steps....138

Change a List....138

Change with steps....139

List assignment and list copy....139

join....140

join list of numbers....140

split....140

for loop on lists....140

in list....141

Where is the element in the list....141

Index improved....141

[].insert....142

[].append....142

[].remove....142

Remove element by index [].pop....142

Remove first element of list....143

Remove several elements of list by index....143

Use list as a queue....143

Queue using deque from collections....144

Fixed size queue....144

List as a stack....145

stack with deque....145

Exercies: Queue....145

Exercise: Stack....146

Solution: Queue with list....146

Solution: Queue with deque....147

Solution: Reverse Polish calculator (stack) with lists....147

Solution: Reverse Polish calculator (stack) with deque....148

Debugging Queue....149

sort....149

sort numbers....150

sort mixed....150

key sort....150

Sort tuples....151

sort with sorted....151

sort vs. sorted....151

key sort with sorted....152

Sorting characters of a string....152

range....152

Looping over index....152

Enumerate lists....153

List operators....153

List of lists....153

List assignment....153

List documentation....154

tuple....154

Exercise: color selector menu....155

Exercise: count digits....155

Exercise: Create list....155

Exercise: Count words....156

Exercise: Check if number is prime....156

Exercise: DNA sequencing....156

Solution: menu....156

Solution: count digits....157

Solution: Create list....158

Solution: Count words....158

Solution: Check if number is prime....159

Solution: DNA sequencing....159

Solution: DNA sequencing with filter....159

Solution: DNA sequencing with filter and lambda....160

[].extend....160

append vs. extend....160

split and extend....160

Files....162

Open and read file....162

Filename on the command line....162

Filehandle with and without....162

Filehandle with return....163

Read file remove newlines....163

Read all the lines into a list....163

Read all the characters into a string (slurp)....163

Not existing file....164

Open file exception handling....164

Open many files - exception handling....164

Writing to file....165

Append to file....165

Binary mode....165

Does file exist? Is it a file?....166

Exercise: count numbers....166

Exercise: strip newlines....166

Exercise: color selector....167

Exercise: ROT13....167

Exercise: Combine lists....167

Solution: count numbers....168

Solution: strip newlines....168

Solution: color selector....168

Solution: Combine lists....169

Read text file....169

Open and read file....169

Direct access of a line in a file....170

Example....170

Dictionary (hash)....172

What is a dictionary....172

When to use dictionaries....172

Dictionary....172

keys....172

Loop over keys....173

Loop using items....173

values....173

Not existing key....174

Get key....174

Does the key exist?....175

Does the value exist?....175

Delete key....175

List of dictionaries....176

Shared dictionary....176

immutable collection: tuple as dictionary key....177

immutable numbers: numbers as dictionary key....177

Sort dictionary by value....178

Sort dictionary keys by value....178

Insertion Order is kept....179

Change order of keys in dictionary - OrderedDict....179

Set order of keys in dictionary - OrderedDict....180

Exercise: count characters....180

Exercise: count words....181

Exercise: count words from a file....181

Exercise: Apache log....182

Exercise: Combine lists again....182

Exercise: counting DNA bases....182

Exercise: Count Amino Acids....183

Exercise: List of dictionaries....183

Exercise: Dictinoary of dictionaries....183

Solution: count characters....184

Solution: count characters with default dict....185

Solution: count words....185

Solution: count words in file....186

Solution: Apache log....187

Solution: Combine lists again....187

Solution: counting DNA bases....187

Solution: Count Amino Acids....188

Loop over dictionary keys....188

Do not change dictionary in loop....189

Default Dict....189

Sets....191

sets....191

set operations....191

set intersection....191

set subset....192

set symmetric difference....192

set union....193

set relative complement....193

set examples....194

defining an empty set....194

Adding an element to a set (add)....194

Merging one set into another set (update)....195

Functions (subroutines)....196

Defining simple function....196

Defining a function....196

Parameters can be named....196

Mixing positional and named parameters....197

Default values....198

Several defaults, using names....198

Arbitrary number of arguments *....198

Fixed parmeters before the others....199

Arbitrary key-value pairs in parameters **....200

Extra key-value pairs in parameters....200

Every parameter option....200

Duplicate declaration of functions (multiple signatures)....200

Recursive factorial....201

Recursive Fibonacci....201

Non-recursive Fibonacci....202

Unbound recursion....202

Variable assignment and change - Immutable....202

Variable assignment and change - Mutable....203

Parameter passing of functions....203

Passing references....203

Function documentation....204

Sum ARGV....204

Copy-paste code....205

Copy-paste code fixed....205

Copy-paste code further improvement....206

Palindrome....206

Exercise: statistics....207

Exercise: recursive....207

Exercise: Tower of Hanoi....207

Exercise: Merge and Bubble sort....207

Solution: statistics....207

Solution: recursive....208

Solution: Tower of Hanoi....209

Solution: Merge and Bubble sort....209

Modules....211

Before modules....211

Create modules....211

path to load modules from - The module search path....212

sys.path - the module search path....212

Flat project directory structure....212

Absolute path....212

Relative path....213

Python modules are compiled....213

How “import” and “from” work?....214

Runtime loading of modules....214

Conditional loading of modules....214

Duplicate importing of functions....214

Script or library....215

Script or library - import....215

Script or library - from import....216

assert to verify values....216

mycalc as a self testing module....217

doctest....217

Scope of import....218

Export import....218

Export import with all....219

import module....220

Execute at import time....220

Import multiple times....220

Exercise: Number guessing....221

Exercies: Scripts and modules....221

Exercise: Module my_sum....221

Exercise: Convert your script to module....222

Exercise: Add doctests to your own code....222

Solution: Module my_sum....222

Regular Expressions....224

What are Regular Expressions (aka. Regexes)?....224

What are Regular Expressions good for?....224

Examples....224

Where can I use it ?....225

grep....225

Regexes first match....225

Match numbers....226

Capture....226

Capture more....227

Capture even more....227

findall....227

findall with capture....228

findall with capture more than one....228

Any Character....228

Match dot....229

Character classes....229

Common characer classes....230

Negated character class....230

Optional character....230

Regex 0 or more quantifier....231

Quantifiers....231

Quantifiers limit....231

Quantifiers on character classes....231

Greedy quantifiers....232

Minimal quantifiers....232

Anchors....233

Anchors on both end....234

Match ISBN numbers....234

Matching a section....235

Matching a section - minimal....236

Matching a section negated character class....237

DOTALL S (single line)....237

MULTILINE M....237

Two regex with logical or....238

Alternatives....238

Grouping and Alternatives....239

Internal variables....239

More internal variables....239

Regex DNA....239

Regex IGNORECASE....240

Regex VERBOSE X....240

Substitution....241

findall capture....241

Fixing dates....242

Duplicate numbers....243

Remove spaces....243

Replace string in assembly code....243

Full example of previous....245

Split with regex....246

Exercises: Regexes part 1....247

Exercise: Regexes part 2....248

Exercise: Sort SNMP numbers....248

Exercise: parse hours log file and give report....249

Exercise: Parse ini file....250

Exercise: Replace Python....250

Exercise: Extract phone numbers....250

Solution: Sort SNMP numbers....251

Solution: parse hours log file and give report....252

Solution: Processing INI file manually....253

Solution: Processing config file....254

Solution: Extract phone numbers....254

Regular Expressions Cheat sheet....255

Fix bad JSON....255

Fix very bad JSON....256

Raw string or escape....257

Remove spaces regex....257

Regex Unicode....258

Anchors Other example....258

Python standard modules....260

Some Standard modules....260

sys....260

Writing to standard error (stderr)....261

Current directory (getcwd, pwd, chdir)....261

OS dir (mkdir, makedirs, remove, rmdir)....261

python which OS are we running on (os, platform)....261

Get process ID....262

OS path....262

Traverse directory tree - list directories recursively....262

os.path.join....263

Directory listing....263

expanduser - handle tilde ~....263

Listing specific files using glob....263

External command with system....263

subprocess....264

subprocess in the background....264

Accessing the system environment variables from Python....265

Set env and run command....265

shutil....265

time....266

sleep in Python....266

timer....266

Current date and time datetime now....267

Converting string to datetime....267

datetime arithmeticis....268

Rounding datetime object to nearest second....268

Signals and Python....268

Sending Signal....268

Catching Signal....269

Catching Ctrl-C on Unix....269

Catching Ctrl-C on Unix confirm....270

Alarm signal and timeouts....270

deep copy list....270

deep copy dictionary....272

Exercise: Catching Ctrl-C on Unix 2nd time....273

Exercise: Signals....273

Ctrl-z....273

JSON....274

JSON - JavaScript Object Notation....274

dumps....274

loads....275

dump....275

load....276

Round trip....276

Pretty print JSON....276

Sort keys in JSON....277

Set order of keys in JSON - OrderedDict....278

Exercise: Counter in JSON....278

Exercise: Phone book....279

Exercise: Processes....279

Solution: Counter in JSON....279

Solution: Phone book....280

Command line arguments with argparse....281

Modules to handle the command line....281

argparse....281

Basic usage of argparse....281

Positional argument....282

Many positional argument....283

Convert to integers....283

Convert to integer....284

Named arguments....284

Boolean Flags....285

Short names....285

Exercise: Command line parameters....286

Exercise: argparse positional and named....286

Exception handling....287

Hierarchy of calls....287

Handling errors as return values....287

Handling errors as exceptions....287

A simple exception....288

Working on a list....288

Catch ZeroDivisionError exception....289

Module to open files and calculate something....290

File for exception handling example....290

Open files - exception....291

Handle divide by zero exception....291

Handle files - exception....292

Catch all the exceptions and show their type....292

List exception types....293

Exceptions....294

How to raise an exception....294

Stack trace....294

Exercies: Exception int conversion....295

Exercies: Raise Exception....296

Solution: Exception int conversion (specific)....296

Solution: Exception int conversion (all other)....297

Solution: Raise Exception....297

Classes - OOP - Object Oriented Programming....298

Why Object Oriented Programming?....298

Generic Object Oriented Programming terms....298

OOP in Python....298

OOP in Python (numbers, strings, lists)....298

OOP in Python (argparse)....299

Create a class....299

Import module containing class....300

Import class from module....300

Initialize a class - constructor, attributes....300

Attributes are not special....300

Create Point class....301

Initialize a class - constructor, attributes....301

Methods....301

Stringify class....302

Inheritance....302

Inheritance - another level....303

Modes of method inheritance....303

Modes of method inheritance - implicit....304

Modes of method inheritance - override....304

Modes of method inheritance - extend....304

Modes of method inheritance - delegate - provide....305

Composition - Line....305

Some comments....306

Class in function....306

Serialization of instances with pickle....306

Quick Class definition and usage....307

Exercise: Add move_rad to based on radians....307

Exercise: Improve previous examples....307

Exercise: Polygon....307

Exercise: Number....308

Exercise: Library....308

Exercise: Bookexchange....308

Exercise: Represent turtle graphics....308

Solution - Polygon....309

PyPi - Python Package Index....310

What is PyPi?....310

Easy Install....310

pip....310

Upgrade pip....310

PYTHONPATH....310

Virtualenv....310

Virtualenv for Python 3....311

SQLite Database Access....312

SQLite....312

Connecting to SQLite database....312

Create TABLE in SQLite....312

INSERT data into SQLite database....312

SELECT data from SQLite database....313

A counter....314

MySQL....316

Install MySQL support....316

Create database user (manually)....316

Create database (manually)....316

Create table (manually)....316

Connect to MySQL....317

Connect to MySQL and Handle exception....317

Select data....318

Select more data....318

Select all data fetchall....318

Select some data fetchmany....319

Select some data WHERE clause....319

Select into dictionaries....320

Insert data....321

Update data....321

Delete data....321

Exercise MySQL....322

Exercise: MySQL Connection....322

Solution: MySQL Connection....322

PostgreSQL....324

PostgreSQL install....324

Python and Postgresql....324

PostgreSQL connect....324

INSERT....324

INSERT (from command line)....325

SELECT....325

DELETE....325

SQLAlchemy....327

SQLAlchemy hierarchy....327

SQLAlchemy engine....327

SQLAlchemy autocommit....327

SQLAlchemy engine CREATE TABLE....327

SQLAlchemy engine INSERT....328

SQLAlchemy engine SELECT....328

SQLAlchemy engine SELECT all....328

SQLAlchemy engine SELECT fetchall....329

SQLAlchemy engine SELECT aggregate....329

SQLAlchemy engine SELECT IN....329

SQLAlchemy engine SELECT IN with placeholders....329

SQLAlchemy engine connection....330

SQLAlchemy engine transaction....330

SQLAlchemy engine using context managers....331

Exercise: Create table....331

SQLAlchemy Metada....332

SQLAlchemy types....333

SQLAlchemy ORM - Object Relational Mapping....333

SQLAlchemy ORM create....333

SQLAlchemy ORM schema....334

SQLAlchemy ORM reflection....335

SQLAlchemy ORM INSERT after automap....335

SQLAlchemy ORM INSERT....336

SQLAlchemy ORM SELECT....336

SQLAlchemy ORM SELECT cross tables....336

SQLAlchemy ORM SELECT and INSERT....337

SQLAlchemy ORM UPDATE....337

SQLAlchemy ORM logging....338

Solution: Create table....338

Exercise: Inspector....339

SQLAlchemy CREATE and DROP....339

SQLAlchemy Notes....340

SQLAlchemy Meta SQLite CREATE....340

SQLAlchemy Meta Reflection....341

SQLAlchemy Meta INSERT....341

SQLAlchemy Meta SELECT....341

NoSQL....342

Types of NoSQL databases....342

MongoDB....343

MongoDB CRUD....343

Install MongoDB support....343

Python MongoDB insert....343

MongoDB CLI....343

Python MongoDB find....344

Python MongoDB find refine....344

Python MongoDB update....344

Python MongoDB remove (delete)....345

Redis....346

Redis CLI....346

Redis list keys....346

Redis set get....346

Redis incr....347

Redis incrby....347

Redis setex....347

Web client....348

urllib the web client....348

urllib2 the web client....348

httpbin.org....348

requests get....349

Download image using requests....349

Download image as a stream using requests....349

Download zip file....349

Extract zip file....350

Interactive Requests....350

requests get JSON....350

requests get JSON UserAgent....350

requests get JSON UserAgent....350

requests get header....351

requests change header....351

requests post....351

Tweet....352

API config file....352

bit.ly....352

Exercise: Combine web server and client....353

Python Web server....354

Hello world web....354

Dump web environment info....354

Web echo....355

Web form....355

Resources....356

Python Flask....357

Python Flask intro....357

Python Flask installation....357

Flask: Hello World....357

Flask hello world + test....357

Flask generated page - time....358

Flask: Echo GET....358

Flask: Echo POST....359

Flask: templates....360

Flask: templates....361

Flask: templates with parameters....361

Flask: runner....362

Exercise: Flask calculator....362

Static files....362

Flask Logging....363

Flask: Counter....363

Color selector without session....363

Session management....364

Flask custom 404 page....364

Flask Error page....365

Flask URL routing....366

Flask Path params....366

Flask Path params (int)....366

Flask Path params add (int)....367

Flask Path params add (path)....367

Jinja loop, conditional, include....368

Exercise: Flask persistent....369

Exercise: Flask persistent....369

Flask Exercises....369

Flask login....369

Flask JSON API....370

Flask and AJAX....371

Flask and AJAX....373

passlib....374

Flask Testing....375

Flask Deploy app....375

Flask Simple Authentication + test....376

Flask REST API....377

Flask REST API - Echo....377

Flask REST API - parameters in path....378

Flask REST API - parameter parsing....378

Flask REST API - parameter parsing - required....379

Networking....381

Secure shell....381

ssh....381

ssh from Windows....381

Parallel ssh....382

telnet....382

prompt for password....382

Python nmap....383

ftp....383

Interactive shell....385

The Python interactive shell....385

REPL - Read Evaluate Print Loop....385

Using Modules....386

Getting help....386

Exercise: Interactive shell....387

Testing Demo....388

How do you test your code?....388

What is testing?....388

What is testing really?....388

Testing demo - AUT - Application Under Test....388

Testing demo - use the module....388

Testing demo: doctets....389

Testing demo: Unittest success....389

Testing demo: Unittest failure....390

Testing demo: pytest using classes....390

Testing demo: pytest without classes....391

Testing demo: pytest run doctests....392

Testing demo: pytest run unittest....392

Exercise: Testing demo....392

Solution: Testing demo....392

Types in Python....394

mypy....394

Types of variables....394

Types of function parameters....394

Types used properly....395

TODO: mypy....395

Testing Intro....396

The software testing equasion....396

The software testing equasion (fixed)....396

The pieces of your software?....396

Manual testing....396

What to tests?....397

Continuous Integration....397

Functional programming....398

Functional programming....398

Iterators (Iterables)....398

range....399

range with list....400

range vs. list size....401

for loop with transformation....401

map....402

map delaying function call....404

map on many values....405

map with list....406

double with lambda....406

What is lambda in Python?....407

lambda returning tuple....408

map returning tuples....408

lambda with two parameters....408

map for more than one iterable....409

map on uneven lists....409

replace None (for Python 2)....409

map on uneven lists - fixed (for Python 2)....410

map mixed iterators....410

map fetch value from dict....410

Exercise: string to length....411

Exercise: row to length....411

Exercise: compare rows....411

Solution: string to length....411

Solution: row to length....411

Solution: compare rows....411

filter....412

filter with lambda....412

filter - map example....413

filter - map in one expression....413

Get indexes of values....414

reduce....415

reduce with default....416

zip....416

Creating dictionary from two lists using zip....416

all, any....417

Compare elements of list with scalar....417

List comprehension - double....417

List comprehension - simple expression....418

List generator....418

List comprehension....419

Dict comprehension....419

Lookup table with lambda....419

Read lines without newlines....420

Read key-value pairs....420

Create index-to-value mapping in a dictionary based on a list of values....421

Exercise: min, max, factorial....421

Exercise: Prime numbers....421

Exercise: Many validator functions....421

Exercise: Calculator using lookup table....421

Exercise: parse file....422

Solution: min, max, factorial....423

Solution: Prime numbers....423

Solution: Many validator functions....423

Solution: Calculator using lookup table....424

map with condtion....424

map with lambda....424

map with lambda with condition....425

List comprehension - complex....425

Iterators - with and without Itertools....426

Advantages of iterators and generators....426

The Fibonacci research institute....426

Fibonacci plain....426

Fibonacci copy-paste....426

Iterators Glossary....427

What are iterators and iterables?....427

A file-handle is an iterator....428

range is iterable but it is not an iterator....428

Iterator: a counter....429

Using iterator....430

Iterator without temporary variable....430

The type of the iterator....430

Using iterator with next....431

Mixing for and next....431

Iterable which is not an iterator....432

Iterator returning multiple values....432

Range-like iterator....433

Unbound or infinite iterator....433

Unbound iterator Fibonacci....434

Operations on Unbound iterator....435

itertools....436

itertools - count....436

itertools - cycle....436

Exercise: iterators - reimplement the range function....437

Exercise: iterators - cycle....437

Exercise: iterators - alter....437

Exercise: iterators - limit Fibonacci....437

Exercise: iterators - Fibonacci less memory....437

Exercise: read char....437

Exercise: read section....438

Exercise: collect packets....438

Exercise: compare files....439

Solution: iterators - limit Fibonacci....440

Solution: iterators - Fibonacci less memory....440

Solution: read section....441

Solution: compare files....441

Solution: collect packets....442

Generators and Generator Expressions....444

Generators Glossary....444

Iterators vs Generators....444

List comprehension and Generator Expression....444

List comprehension vs Generator Expression - less memory....445

List comprehension vs Generator Expression - lazy evaluation....446

Generator: function with yield - call next....447

Generators - call next....448

Generator with yield....449

Generators - fixed counter....449

Generators - counter....449

Generators - counter with parameter....450

Generators - my_range....450

Fibonacci - generator....451

Infinite series....452

Integers....452

Integers + 3....452

Integers + Integers....453

Filtered Fibonacci....453

The series.py....454

generator - unbound count (with yield)....454

iterator - cycle....455

Exercise: Alternator....455

Exercise: Prime number generator....456

Exercise: generator....456

Exercise: Tower of Hanoi....456

Exercise: Binary file reader....456

Exercise: File reader with records....456

Logging....458

Simple logging....458

Simple logging - set level....458

Simple logging to a file....458

Simple logging format....459

Simple logging change date format....459

getLogger....459

Time-based logrotation....460

Size-based logrotation....460

Closures....461

Counter local - not working....461

Counter with global....461

Create incrementors....462

Create internal function....462

Create function by a function....463

Create function with parameters....463

Counter closure....464

Make incrementor with def (closure)....464

Make incrementor with lambda....465

Exercise: closure bank....465

Solution: closure bank....466

Solution: counter with parameter....467

Decorators....469

Function assignment....469

Function inside other function....469

Decorator....470

Use cases for decorators in Python....470

A recursive Fibonacci....471

trace fibo....471

tron decorator....472

Decorate with direct call....472

Decorate with parameter....472

Decorator accepting parameter....472

Decorate function with any signature....473

Decorate function with any signature - implementation....473

Exercise: Logger decorator....474

Exercise: memoize decorator....474

Solution: Logger decorator....474

Solution: Logger decorator (testing)....475

Solution memoize decorator....475

Context managers (with statement)....478

Why use context managers?....478

Context Manager examples....479

cd in a function....479

open in function....481

open in for loop....482

open in function using with....482

Plain context manager....483

Param context manager....484

Context manager that returns a value....484

Use my tempdir - return....485

Use my tempdir - exception....486

cwd context manager....486

tempdir context manager....487

Context manager with class....488

Context managers with class....489

Context manager: with for file....490

With - context managers....490

Exercise: Context manager....490

Exercise: Tempdir on Windows....491

Solution: Context manager....491

Advanced lists....493

Change list while looping: endless list....493

Change list while looping....493

Copy list before iteration....494

for with flag....494

for else....494

enumerate....495

do while....495

list slice is copy....496

Advanced Exception handling....497

Exceptions else....497

Exceptions finally....497

Exit and finally....498

Catching exceptions....499

Home made exception....499

Home made exception with attributes....500

Home made exception hierarcy....500

Home made exception hierarcy - 1....501

Home made exception hierarcy - 2....501

Home made exception hierarcy - 3....502

Exercise: spacefight with exceptions....502

Exercies: Raise My Exception....503

Solution: spacefight with exceptions....504

Solution: Raise My Exception....505

Exception finally return....506

Warnings....507

Warnings....507

CSV....508

Reading CSV the naive way....508

CSV with quotes and newlines....508

Reading a CSV file....509

CSV dialects....509

CSV to dictionary....510

Exercise: CSV....511

Solution: CSV....511

Excel....512

Spreadsheets....512

Python Excel....512

Create an Excel file from scratch....512

Worksheets in Excel....513

Add expressions to Excel....513

Format field....513

Number series and chart....514

Read Excel file....515

Update Excel file....515

Exercise: Excel....516

XML....517

XML Data....517

Expat - Callbacks....517

XML DOM - Document Object Model....518

XML SAX - Simple API for XML....518

SAX collect....519

XML elementtree....520

SciPy - for Scientific Computing in Python....522

Data Science tools in Python....522

Data Analysis resources....523

Python and Biology....524

Biopython....524

Biopython background....524

Bio python sequences....524

Download data....524

Read FASTA, GenBank files....525

Search nucleotids....525

Download nucleotids....526

Exercise: Nucleotid....526

Biology background....526

Chemistry....528

Chemistry links....528

Bond length....528

Covalent radius....528

Python energy landscape explorer....529

Other chemistry links....529

numpy....530

What is NumPy....530

Numpy - vector....530

NumPy 2D arrays....530

Numpy - set type....531

NumPy arrays: ones and zeros....531

Numpy: eye....531

NumPy array random....532

NumPy Random integers....532

NumPy array type change by division (int to float)....533

Numpy: Array methods: transpose....533

Numpy: reference, not copy....534

Numpy: copy array....534

Numpy: Elementwise Operations on Arrays....534

Numpy: multiply, matmul, dot for vectors....535

Numpy: multiply, matmul, dot for vector and matrix....535

Numpy: multiply, matmul, dot for matrices....536

Numpy: casting - converting from strings to integer.....537

Numpy: indexing 1d array....538

Numpy: slice is a reference....538

Numpy: slice - copy....538

Numpy: abs value on a Numpy array....538

Numpy: Logical not on a Numpy array....539

Numpy: Vectorize a function....540

Numpy: Vectorize len....540

Numpy: Vectorize lambda....541

Numpy: Filtering array....541

Numpy: Filter matrix values....541

Numpy: Filter matrix rows....542

Numpy: Stat....543

Numpy: Serialization....543

Numpy: Load from Matlab file....543

Numpy: Save as Matlab file....544

Numpy: Horizontal stack vectors (hstack)....544

Numpy: Append or vertically stack vectors and matrices (vstack)....545

Numpy uint8....545

Numpy int8....546

Pandas....547

Pandas....547

Planets....547

Pandas Planets - Dataframes....547

Pandas Stocks....548

Pandas Stocks....548

Merge Dataframes....549

Analyze Alerts....549

Analyze IFMetrics....549

Create Excel file for experiment with random data....550

Calculate Genome metrics....550

Calculate Genome metrics - add columns....551

Calculate Genome metrics - vectorized....552

Calculate Genome metrics - vectorized numpy....552

Genes using Jupyter....553

Combine columns....553

Pandas more....553

Pandas Series....554

Pandas Series with names....555

Matplotlib....556

About Matplotlib....556

Matplotlib Line....556

Matplotlib Line with dates....556

Matplotlib Simple Pie....557

Matplotlib Simple Pie with params....558

Matplotlib Pie....558

Matplotlib Pie 2....559

Plot, scatter, histogram....560

Seaborn....561

Searborn use examples....561

Seaborn tip....561

Seaborn Anscombes Quartet....562

Jupyter notebooks....563

Jupyter on Windows....563

Jupyter on Linux and OSX....563

Jupyter add....563

Planets....563

Jupyter notebook Planets....565

Jupyter StackOverflow....565

Jupyter StackOverflow - selected columns....566

Jupyter processing chunks....566

Jupyter StackOverflow - selected rows....566

Jupyter StackOverflow - biggest countries (in terms of number of responses)....566

Jupyter StackOverflow - historgram....567

Jupyter StackOverflow - filter by country....567

Jupyter StackOverflow - OpenSourcer....567

Jupyter StackOverflow - cross tabulation....567

Jupyter StackOverflow - salaries....568

Jupyter StackOverflow - replace values....568

Jupyter StackOverflow - selected rows....568

Jupyter notebook Intellisense (TAB completition)....569

Jupyter examples....569

IPy Widgets....569

Testing....570

Traditional Organizations....570

Quality Assurance....570

Web age Organizations....570

TDD vs Testing as an Afterthought....571

Why test?....571

Testing Modes....571

Testing Applications....572

Testing What to test?....572

Testing in Python....572

Testing Environment....572

Testing Setup - Fixture....573

Testing Resources....573

Testing with unittest....574

Use a module....574

Test a module....574

The tested module....575

Testing - skeleton....575

Testing....576

Test examples....576

Testing with PyTest....578

Pytest features....578

Pytest setup....578

Testing with Pytest....578

Testing functions....579

Testing class and methods....579

Pytest - execute....579

Pytest - execute....579

Pytest simple module to be tested....580

Pytest simple tests - success....580

Pytest simple tests - success output....580

Pytest simple tests - failure....580

Pytest simple tests - failure output....581

Exercise: test math functions....581

Exercise: test this app....581

Exercise: test the csv module....582

Solution: Pytest test math functions....582

Solution: Pytest test this app....582

Solution: test the csv module....583

PyTest bank deposit....583

PyTest expected exceptions (bank deposit)....583

PyTest expected exceptions (bank deposit) - no exception happens....584

PyTest expected exceptions (bank deposit) - different exception is raised....584

PyTest expected exceptions....585

PyTest expected exceptions output....585

PyTest expected exceptions (text changed)....585

PyTest expected exceptions (text changed) output....585

PyTest expected exceptions (other exception)....585

PyTest expected exceptions (other exception) output....586

PyTest expected exceptions (no exception)....586

PyTest expected exceptions (no exception) output....586

PyTest: Multiple Failures....586

PyTest: Multiple Failures output....587

PyTest Selective running of test functions....587

PyTest: stop on first failure....587

Pytest: expect a test to fail (xfail or TODO tests)....587

Pytest: expect a test to fail (xfail or TODO tests)....588

PyTest: show xfailed tests with -rx....588

Pytest: skipping tests....588

Pytest: show skipped tests woth -rs....589

Pytest: show extra test summmary info with -r....589

Pytest: skipping tests output in verbose mode....590

Pytest verbose mode....590

Pytest quiet mode....590

PyTest print STDOUT and STDERR using -s....590

PyTest failure reports....591

PyTest compare numbers....591

PyTest compare numbers relatively....591

PyTest compare strings....592

PyTest compare long strings....592

PyTest is one string in another strings....592

PyTest test any expression....593

PyTest element in list....593

PyTest compare lists....593

PyTest compare short lists....594

PyTest compare short lists - verbose output....594

PyTest compare dictionaries....594

PyTest compare dictionaries output....595

PyTest Fixtures....595

PyTest Fixture setup and teardown....595

PyTest Fixture setup and teardown output....596

PyTest: Class setup and teardown....596

PyTest: Class setup and teardown output....597

Pytest Dependency injection....597

Pytest fixture - tmpdir....597

Pytest capture STDOUT and STDERR with capsys....598

Pytest Fixture - home made fixtures....598

More fixtures....599

Pytest: Mocking - why?....601

Pytest: Mocking - what?....601

Pytest: One dimensional spacefight....601

Pytest: Mocking input and output....602

Pytest: Mocking random....602

Pytest: Flask echo....603

Pytest: testing Flask echo....603

PyTest: Run tests in parallel with xdist....604

PyTest: Order of tests....604

PyTest: Randomize Order of tests....604

PyTest: Force default order....604

PyTest: no random order....605

Anagram on the command line....605

PyTest testing CLI....605

PyTest test discovery....606

PyTest test discovery - ignore some tests....606

PyTest select tests by name....607

PyTest select tests by marker....607

PyTest: Test Coverage....608

Exercise: module....608

Exercise: Open Source....609

Pytest resources....609

Pytest and tempdir....609

PyTest compare short lists - output....610

PyTest with parameter....610

PyTest with parameters....611

Pytest reporting in JUnit XML format....611

No test selected....612

Advancted functions....613

Variable scopes....613

Name resolution order (LEGB)....613

Scoping: global seen from fuction....613

Assignment creates local scope....613

Local scope gone wrong....614

Changing global variable from a function....614

Global variables mutable in functions....615

Scoping issues....615

sub in sub....616

Scoping sub in sub (enclosing scope)....616

Function objects....616

Functions are created at run time....617

Mutable default....618

Use None as default parameter....618

Inner function created every time the outer function runs....619

Static variable....620

Static variable in generated function....620

Inspect....621

Variable number of function arguments....623

Python function arguments - a reminder....623

Functions with unknown number of argumerns....623

Variable length argument list with * and **....623

Passing arguments as they were received (but incorrectly)....624

Unpacking args before passing them on....624

Exercise: implement the my_sum function....625

Solution: implement the my_sum function....625

Exercise: implement the reduce function....625

Soluton: implement the reduce function....626

Exercise: sort pairs....626

Solution: sort pairs....626

Python Packages....627

Why Create package....627

Create package....627

Internal usage....627

use module in package - relative path....628

use package (does not work)....628

package importing (and exporting) module....628

use package (module) with import....628

use package with import....629

Creating an installable Python package....629

Create tar.gz file....630

Install Package....630

Dependencies....630

Add README file....631

Add README file (setup.py)....631

Include executables....632

Add tests....632

Add tests calc....633

Add tests all....633

setup.py....633

Run tests and create package....634

Packaging applications (creating executable binaries)....634

Using PyInstaller....634

Other PyInstaller examples....634

Other....634

Py2app for Mac....635

Exercise: package....635

Exercise: create executable....635

Ctypes....636

ctypes - hello....636

concat....637

links....638

Advanced OOP....639

Class count instances....639

Class Attributes....639

Class Attributes in Instances....639

Attributes with method access....640

Instance Attribute....640

Methods are class attributes....641

Monkey patching....642

Classes: instance method....642

Class methods and class attributes....643

Classes: constructor....644

Class methods - alternative constructor....644

Abstract Base Class....645

Abstract Base Class with abc....646

ABC working example....647

ABC - cannot instantiate the base-class....647

ABC - must implement methods....647

Use Python @propery to fix bad interface (the bad interface)....647

Use Python @propery to fix bad interface (first attempt)....648

Use Python @propery to fix bad API....648

Use Python @propery decorator to fix bad API....649

Use Python @propery for value validation....649

class and static methods....651

Destructor: del....652

Destructor delayed....652

Destructor delayed for both....653

Opearator overloading....653

Operator overloading methods....654

Exercise: rectangular....654

Exercise: SNMP numbers....654

Exercise: Implement a Gene inheritance model combining DNA....655

Exercise: imaginary numbers - complex numbers....655

Solution: Rectangular....656

Solution: Implement a Gene inheritance model combining DNA....657

Instance counter....658

2to3....659

Convertig from Python 2 to Python 3....659

division....659

print in Python 2....659

print in Python 3....659

input and raw_input....660

Code that works on both 2 and 3....660

Compare different types....660

Octal numbers....660

2to3 Resources....660

Design Patterns....662

What are Design Patterns?....662

Don’t replace built-in objects....662

Facade - simple interface to complex system....662

Monkey Patching....663

Creation DPs “Just One”....663

Singleton....664

Monostate (Borg)....664

Dispatch table....664

Parallel....666

Types of Problems....666

Types of solutions....666

How many parallels to use?....666

Dividing jobs....667

Performance Monitoring....667

Threads....668

Python Threading docs....668

Threaded counters....668

Simple threaded counters....669

Simple threaded counters (parameterized)....670

Pass parameters to threads - Counter with attributes....671

Create a central counter....672

Lock - acquire - release....672

Counter - plain....673

GIL - Global Interpreter Lock....674

Thread load....674

Exercise: thread files....675

Exercise: thread URL requests.....675

Exercise: thread queue....677

Solution: thread queue....678

Solution: thread URL requests.....678

Forking....680

Fork....680

Forking....680

Fork skeleton....681

Fork with load....682

Fork load results....682

Marshalling / Serialization....683

Fork with random....683

Exercise: fork return data....684

Solution: fork return data....684

Asyncronus programming with AsyncIO....686

Sync chores....686

Async chores....687

Explanation....689

Coroutines....689

More about asyncio....690

Async files....690

Asynchronus programming with Twisted....691

About Twisted....691

Echo....691

Echo with log....692

Simple web client....692

Web client....693

Multiprocess....695

Multiprocess CPU count....695

Multiprocess Process....695

Multiprocess N files: Pool....695

Multiprocess load....696

Multiprocess: Pool....697

Multiprocess load async....697

Multiprocess and logging....698

Exercise: Process N files in parallel....699

Exercise: Process N Excel files in parallel....699

Exercise: Fetch URLs in parallel....699

Exercise: Fetch URLs from one site.....701

Solution: Fetch URLs in parallel....702

Multitasking....704

What is Multitasking?....704

Multitasking example....704

Multitasking example with wait....704

Multitaksing - second loop waits for first one....705

Multitasking counter....706

Multitasking counter with thread locking....706

Improving Performance - Optimizing code....708

Problems....708

Optimization strategy....708

Locate the source of the problem....708

Optimizing tactics....708

DSU: Decorate Sort Undecorate....708

Profile code....709

Slow example....709

profile slow code....710

cProfile slow code....710

Benchmarking....711

Benchmarking subs....711

Levenshtein distance....712

Generate words....712

Levenshtein - pylev....713

Levenshtein - edittidtance....713

Editdistance benchmark....713

A Tool to Generate text files....713

Count characters....714

Memory leak....716

Garbage collection....716

Weak reference....716

Exercise: benchmark list-comprehension, map, for....717

Exercise: Benchmark Levenshtein....717

Exercise: sort files....717

Exercise: compare split words:....718

Exercise: count words....718

GUI with Python/Tk....719

Sample Tk app....719

GUI Toolkits....721

Installation....722

Python Tk Documentation....722

Python Tk Button....723

Python Tk Button with action....723

Python Tk Label....723

Python Tk Label - font size and color....724

Python Tk Keybinding....724

Python Tk Entry (one-line text entry)....725

Python Tk Entry for passwords and other secrets (hidden text)....725

Python Tk Checkbox....725

Python Tk Radiobutton....726

Python Tk Listbox....726

Python Tk Listbox Multiple....727

Python Tk Menubar....727

Python Tk Text....728

Python Tk Dialogs....729

Python Tk Filedialog....729

Python Tk messagebox....730

Python Tk Combobox....731

Python Tk OptionMenu....732

Python Tk Scale....732

Python Tk Progressbar....733

Python Tk Frame....733

Not so Simple Tk app with class....734

Tk: Hello World....734

Tk: Quit button....735

Tk: File selector....735

Tk: Checkbox....736

Tk: Runner....737

Tk: Runner with threads....738

Getting started with Tk....740

Exercise: Tk - Calculator one line....742

Exercise: Tk Shopping list....742

Exercise: Tk TODO list....742

Exercise: Tk Notepad....742

Exercise: Tk Copy files....742

Exercise: Tk....743

Solution: Tk - Calculator one line....743

Solution: Tk....744

Solution: Tk Notepad....745

Simple file dialog....746

Python Pitfalls....747

Reuse of existing module name....747

Use the same name more than once....747

Compare string and number....748

Compare different types....749

Sort mixed data....749

Linters....751

Static Code Analyzis - Linters....751

PEP8....751

F811 - redefinition of unused....751

Warn when Redefining functions....751

Python .NET....752

IronPython....752

Use .NET libraries from Python....752

Python and .NET console....753

Python and .NET examples....753

Exercise Python and .NET....755

Python and Java....756

Jython....756

Calling Java from Python....756

Jython - Python running on the JVM....757

Jython Installation....757

Jython Installation....757

Jython load Java class....757

Jython load Java class in code....757

Jython test Java class....758

PIL - Pillow....759

Install Pillow....759

Create First Image....759

Write Text on Image....759

Select font for Text on Image....759

Font directories....760

Get size of an Image....760

Get size of text....760

Resize an existing Image....760

Crop an existing Image....761

Combine two images....761

Rotated text....761

Rotated text in top-right corner....761

Embed image (put one image on another one)....762

Draw a triangle....762

Draw a triangle and write text in it....763

Draw a triangle and write rotated text in it....763

Draw a rectangular....763

Draw a rectangle....764

Draw circle....764

Draw heart....764

Rectangle with rounded corners....765

TODO....765

FAQ....766

How not to name example scirpts?....766

Platform independent code....766

How to profile a python code to find causes of slowness?....767

pdb = Python Debugger....767

Avoid Redefining functions....768

Appendix....769

print_function....769

Dividers (no break or continue)....769

Lambdas....769

Abstract Class....769

Remove file....770

Modules: more....770

import hooks....771

Python resources....771

Progress bar....771

from future....771

Variable scope....772

scope....773

type....774

Look deeper in a list....775

Exercise: iterators - count....775

Simple function (before generators)....775

Other slides....777

Other slides....777

Atom for Python....777

IDLE - Integrated DeveLopment Environment....777

sh-bang - executable on Linux/Apple....778

Strings as Comments....778

pydoc....778

How can I check if a string can be converted to a number?....779

Spyder Intro....779

Interactive Debugging....779

Parameter passing....780

Command line arguments and main....780

Infinite loop....780

break....780

continue....781

While with many conditions....781

while loop with many conditions....782

Format with conversion (stringifiation with str or repr)....782

Name of the current function in Python....783

Name of the caller function in Python....783

Stack trace in Python using inspect....783

Module Fibonacci....784

PyTest - assertion....785

PyTest - failure....785

PyTest - list....786

SAX with coroutine....786

Getting the class name of an object....787

Inheritance - super....788

Inheritance - super - other class....788

iterator - pairwise....789

iterator - grouped....789

itertools - groupby....790

Circular references....790

Context managers: with (file) experiments....791

itertools - izip....791

mixing iterators....791

mixing iterators....792

itertools - pairwise....792

itertools - grouped....792

range vs xrange in Python....793

profile (with hotshot) slow code....793

Abstract Base Class without abc....794

Abstract Base Class with abc Python 2 ?....795

Abstract Base Class with metaclass....795

Create class with metaclass....796

Python Descriptors....798

alter iterator....798

Create a counter queue....799

A Queue of tasks....799

Filtered Fibonacci with ifilter....800

Python from .NET....800

Use this book to write an Ethereum Blockchain Smart Contract, test it, deploy it, and create a web application to interact with your smart contract.

 Beginning Ethereum Smart Contracts Programming is your fastest and most efficient means of getting started if you are unsure where to begin and how to connect to the Ethereum Blockchain. The book begins with a foundational discussion of blockchain and the motivation behind it. From there, you will get up close and personal with the Ethereum Blockchain, learning how to use an Ethereum client (geth) to connect to the Ethereum Blockchain to perform transactions such as sending Ethers to another account.

You will learn about smart contracts without having to wade through tons of documentation. Author Lee's "learn-by-doing" approach will allow you to be productive and feel confident in your ability in no time. The last part of this book covers tokens, a topic that has taken the cryptocurrency market by storm.

 Sample code in Python, Solidity, and jаvascript is provided in the book and online.

What You'll Learn

• Understand the basic premise of blockchain and "record keeping" in a peer-to-peer network
• Experience blockchain in action by creating your own blockchain using Python
• Know the foundation of smart contracts programming and how to deploy and test smart contracts
• Work on a case study to illustrate the use of blockchain
• Be familiar with tokens, and how to create and launch your own ICO digital token
• Write smart contracts that transact using tokens

Who This Book Is For

Those who want to get started quickly with Ethereum Smart Contracts programming. Basic programming knowledge and an understanding of Python or jаvascript is recommended.